FDStream, FDStream: seek(offset, anchor = BEGIN) by default
FDStream, FDStream: seek(offset, anchor = BEGIN) by default

* and we not need pass it explicitly anymore

Change-Id: I80fd2358507700744c721facdc01eeaffe08ef4e
Signed-off-by: Kefu Chai <ef1142690fdf7c5d47bbd7e2a7a410478308cc21@mozy.com>
Reviewed-on: https://gerrit.dechocorp.com/38912
Reviewed-by: Kevin Cai <c4f49ef5a44534d46de426dda18a118a2ca4debf@mozy.com>
Reviewed-by: Jenkins <49695b0f9c673fd73dab0ff3f84b5ced9302cc6a@mozy.com>

mtanski/mordor,adfin/mordor,mozy/mordor,mtanski/mordor,mtanski/mordor,mozy/mordor,mozy/mordor,adfin/mordor,adfin/mordor